[1] "Provide the United States with a forward-deployed, amphibious force-in-readiness capable of executing mission across the full spectrum of combat and military operations other than war."

On its final deployment, the MAU evacuated the Palestine Liberation Organization from Beirut, and was the first American unit to serve in the multi-national peace-keeping force in Lebanon.

On 18 October 1983, the MAU departed the United States, and less than two days into its trans-Atlantic voyage it was diverted to the southern Caribbean.

The MAU remained ashore until late February 1984, when the mission drew to a close, and evacuated hundreds of American citizens from the country.

On 5 February 1988, the word 'Amphibious' was replaced with 'Expeditionary' to reflect the Marine Corps' changing role in national defense and theater security.

In April 1996, the 22nd MEU (SOC) arrived off the coast of civil war torn Liberia in western Africa for Operation Assured Response.

The unit remained at sea until 2 Aug. which the Marines went ashore to reinforce the U.S. Embassy in Monrovia and evacuated U.S. citizens and designated third-country nationals.

The 2005-2006 deployment saw the members of the 22nd MEU in Iraq, battling insurgents from a forward operating base in and around the ancient city of Hīt (pronounced "heet").

Over the course of its time in Iraq, the MEU participated in 14 named operations and uncovered vast quantities of insurgent arms, ammunition and ordnance.

During this time, the MEU participated in 14 named operations and uncovered vast quantities of insurgent arms, ammunition and ordnance.

The MEU's 2007 and 2008 deployment brought the unit to the Bay of Bengal where its members conducted humanitarian relief operations after Tropical Cyclone Sidr struck eastern India and Bangladesh.

Marines and Sailors of the 22nd MEU with the Bataan Amphibious Ready Group (BATARG) wrapped up their deployment and returned home in October 2014.

[9] The 22nd MEU was the first major Marine force to respond, managing the hardest hit area that spanned 65 kilometers (40 mi) west of Port-au-Prince.

The 22nd MEU independently delivered nearly 560,000 liters of bottled water and nearly 195,000 gallons of bulk water; more than 1.6 million pounds of rations and approximately 15,000 pounds of medical supplies, while rotary wing aircraft from the 22nd MEU flew more than 610 flight hours and 618 missions in direct support of Operation Unified Response to aid those affected by the earthquake.

In order to quickly provide sea-based ground troops to support possible ground intervention in Libya, the 22nd Marine Expeditionary Unit deployed in March 2011, 4 months prior to its originally scheduled deployment with Battalion Landing Team 2nd Battalion, 2nd Marines (2/2), Combat Logistics Battalion 22, and Marine Medium Tiltrotor Squadron 263 (VMM 263) aboard USS Bataan, USS Whidbey Island and USS Mesa Verde.

Its 321-day duration fell just eight days short of the record set in 1973 by the aircraft carrier USS Midway for the longest U.S. Navy deployment since World War II.

From February to October of 2014, the 22nd MEU composed of BLT 1/6, Marine Medium Tiltrotor Squadron 263 (VMM-263), and CLB 22 deployed to the 5th and 6th Fleet area of operations.

Also, during the deployment the Bataan and the 22nd MEU supported an assessment of humanitarian options in support of displaced Iraqi civilians trapped on Sinjar Mountain by the Islamic State of Iraq and the Levant and initiated the air campaign against the Islamic State; AV-8B Harriers from the USS Bataan participated in reconnaissance missions and at least one air strike, including the first use of Marine Corps ordnance against an ISIS-controlled target.

[13][14][15] From December 2018 to July 2019, 22nd MEU deployed to the 5th and 6th Fleet areas of responsibility as part of the KEARSARGE Amphibious Ready Ground (KSG/ARG).